How this story came together

To report this series, Neil Swidey interviewed people involved at all levels of the project and accident, from divers and their families to lawyers, engineers, and public officials. He also reviewed thousands of pages of documents, including investigative reports, depositions, contemporaneous notes, construction and design documents, and contracts and memos, and he viewed video footage taken inside the tunnel during the project. Although Harald Grob did not agree to be interviewed for this series, he had been interviewed at length by both investigators and lawyers, and the notes from those conversations were used in the preparation of this report. When dialogue is quoted, it is based either on firsthand documents or the recollections of at least one, usually more, participant in the conversation.